“I always thought I’d be scared, but I’m ready,” Kelley tells PEOPLE. “I’m 27, and I feel I’ve done more than most people will do in a lifetime. I’m ready to settle down, start a family and build my Kelley empire.”

The couple, who met when Heigl appeared in a video for Kelley’s song “Only You,” got engaged in June 2006. They have not revealed a wedding date, but Kelly is sure the 28-year-old Grey’s Anatomy actress is the one.

“She’s so great,” he says. “We’re both kind of carbon copies of each other in some ways, and we have our differences, which makes things fun and exciting.”

The prospect of tying the knot has even inspired Kelley’s latest material. “I just finished a new album called Special Company, which sort of takes you through the emotional roller coaster of getting married,” he says. “I’m about to become a real man.”

Are kids on the horizon? “We haven’t talked about it,” Kelley says. “We throw around names, but it’s just for fun.”

Kelley was performing in Las Vegas on Sunday night, as part of the Hennessey Artistry Concert Tour, and couldn’t be in L.A. to see his girlfriend snag the Emmy for best supporting actress in a drama. But he got the news immediately, with a little help from his friends.

“My manager put her phone up to her TV so I could hear the acceptance speech,” he said. “It’s beautiful. She works so hard, and she’s so deserving of it.”

The couple soon spoke by phone, and it was clear the actress was over the moon. “I couldn’t even understand what she was saying because she was so excited,” Kelley says. “It was awesome.”